Tuesday, September 16, 2014

War Stories - Episode 27: The Spring's the Thing - Fun with Business Cars


I imagine the conversation went something like this:

Stanley Crane:  "What's our track geometry car tell us about slow orders on the Pittsburgh Line?"

Others: "Uh, we don't have a geometry car."

Stanley Crane:  "What?  No track geometry car?  How do you know how the track reacts under load?"

Others:  "We don't"

Stanley Crane:  "Well, we should have one!  Go see what the Southern has and then get me one.  And make sure it weighs the same as a loaded 100 ton car."

Others:  "Yes, sir."

Okay.  Probably not exactly like that.  But, Stanley Crane wanted Conrail to have a track geometry car.

Responsibility for creating such a beast fell largely on the Equipment Engineering Department.  The MOW department handled the fancy track measuring system, but the converting the basic car structure fell on the department I was in.  There were still a few "old heads" from the NYC and PRR passenger days around who knew their stuff when it came to passenger car engineering.  I was one of the "new guys" who didn't know much but I learned a lot rubbing shoulders with the "old heads."  There was enough work to go around and they let me in on the project.

A design emerged.  Find a suitable heavyweight car with good, cast, equalized six axle trucks.  Ballast the centersill to get the car up to 263,000 pounds, fit out the interior, install track geometry equipment and, voila, a geometry car!

A candidate car was secured from ATSF, a spec written and a contract was let out to Amtrak Beach Grove to do the work.

One job that fell to me was to create a list of equipent and supplies needed for the on board crew to maintain the car.  This was primarily cleaning supplies, but included stuff needed to keep the undercar engine-generator set running.  Not very glamorous.  I'm not sure why the MOW crew taht would be manning the car didn't handle this, but, never-the-less, I poured over catalogs and came up with a long list of stuff to buy.  Everything from long-handled squeegees for window cleaning to, engine oil, to a Hoover vacuum cleaner.

Another job was on-board fire suppression.  The car needed a system for the under-car engine generator set as well as the living spaces.  I knew nothing about fire suppression systems, so I cast about the yellow pages looking for some local vendors and basically took the first one who I called who was interested.

Bad decision.

We got a functional system on the car, but a lot of the badges and labels supplied looked like the guy did them in his basement with a rattle-can of spray paint and some peel-and-stick lettering from the local ACE hardware.  Live and learn...or live and suffer?  The fire suppression guy turned out to be a chain smoker.  I don't think he took a single breath ever that wasn't though a lit cigarrette.  Does that make it odd or fitting that he was in the fire suppression business?

The best job was helping my boss out with spring design for the car.  Once we had a good solid estimate of the car's weight, we had to design a set of springs to fit the truck spring pockets that would function.  The trucks were designed for a 70 ton passenger car and had accordingly-sized spring pockets.  The trucks themselves could handle the new, 130 ton weight.  They were of a good cast steel design and survived the stress analysis cut.

We created a simple spreadsheet program to handle the spring design using well-known spring design criteria.  We soon realized we had a problem.  Even using the best steel and manufacturing processes and the most nested coils we could fit, we either had to have very stiff springs or very short travel.  We messed around with all possible combinations of wire size and turns, finally settling on the softest set we could create with barely adequate travel.

Along the way, I got a nice trip to Amtrak's Beech Grove Shops to see the car under construction.  A neat old backshop.  Amtrak had a good amount of their own work going on, plus they were assembling the latest order of transit cars for WMATA.  Tucked away in the corner, was CR21 under construction.  Amtrak was doing first-rate work on the car. It was clear we had chosen a competent vendor.

Finally, the car was done.

The MOW department started using the car.

The MOW department started complaining.

"The car rides rough!" they said.  Uh, oh. Arrange for a quick ride quality test.

I'm not sure if the test lab helped on on this one or not, but a quick ride from Altoona to Conway showed the car rode stiffly.  The ride was perfectly safe, just a bit stiff.  More like a sports car than a Cadillac. The good news was the springs didn't bottom out or run out of lateral suspension anywhere - even when we went around a 50 mph curve at 70 mph!  Oops.  That's what happens when freight engineers pilot passenger trains...  A glace at the track chart - curve was 50 freight, 60 passenger.  The engineer "forgot".

They ran the car a few more months and the complaints kept up.  This time, we got the lab involved.  They did some interesting static testing where they jacked up the car on some explosive blocks -

Wait, what?  Explosive blocks!  Yep.  The lab got to play with lots of cool things.

- and then let the car free-fall a couple inches, measuring the suspension response.

They didn't find anything surprising.  They measured a vertical natural frequency of roughly 1 Hz.  A typical passenger car has a suspension natural frequency of 0.5 Hz.  That exactly matched our theoretical calculations - it's really just a mass on a spring - square root of  k/M, right?

Checked with Southern about their car.  Turns out it was overweight - nearly 300,000#.  They had traded nearly all spring travel for softness.  They said they replaced the springs quite often.  The car must have spent quite a bit of time with the secondaries bottoming out and the primaries taking up the slack.  We didn't care for that approach even a little.

We went back to the drawing board and traded off some suspension travel for softness.  A new set of springs was ordered and installed.  There was no way we could get all the way to 0.5Hz, but we did nudge it down a bit closer.  The car went back out.  A year later, more complaints.

This time I borrow Amtrak's accelerometer and meet the car in Selkirk.  I ride to Buffalo.  You'd think we'd be able get there as fast as an Amtrak train.  Slightly lower maximum speed, but no stops.

Good theory.

Just wrong!

The gang that ran the geometry car had some interesting marching orders from day one:  "Do not miss one inch your assigned route!"  The crew took that as gospel and almost immediately got themselves in hot water with the operating folk on every division.

The gauge measuring arms on the car were cranky.  For reasons unknown, they had a tendancy to hop up on top of the rail every now and then.  Sometimes, the crew could coerce them back down.  Sometimes they'd  have to losen some bolts and retighten them.  Sometimes, they had to remove them completely and install the spares on board.  They never knew what it would take until they got into it.  One thing they NEVER did was drag the car into the clear somewhere and work on it there and perhaps skip a dozen miles or so on this pass.  They HAD to cover every inch - and they had to do their repairs RIGHT THERE.  There was no negotiation.  I believe there were some personality issues and pride at stake.  I kept my mouth shut - always.  (See, I can learn!)

One particular time, legend has it, they got hung up on the busy single track portion of the River Line and took hours to make their repairs.  This did not endear them with the dispatcher who wanted to use his railroad to run some trains.  There were other rumors from other divisions of geometry car transgressions.  Needless to say, train dispatchers got very gun-shy with the car.  They'd only give it the railroad when the absolutely had to and when traffic in the area was light.  Consequently, the car never made the miles each day it was supposed to, despite long days worked by the crew.

This was both good and bad for me.  Bad because I didn't get all that many miles to test despite having a relatively long day of work.  But, good, because the dispatcher would hold us on controlled sidings all over the place and run traffic by, around and through us.  It gave me a good excuse to go out and "check the trucks", taking my camera with me.  I would take some pictures of the trucks and suspension, feel the roller bearings for heat, and then just hang around outside and "railfan" until it was time to go.

Ready to depart Selkirk
In the hole (again!)

Amtrak from the east and...

Amtrak from the west while we sit and wait.
The second set of springs were better, but there could not be a "best" set.  You just can't stuff 130 tons of springing in a 70 ton spring pocket!  The CR21 crew finally decided to drop their maximum speed from 70 to 60 mph.  Part of it was ride quality and part of it was the whole issue of trying to keep their gauge measuring arms from derailing.  They were loathe to do it, though, since they thought it would reduce their daily mileage.  Gee, maybe if they didn't stop dead on main tracks every time they needed to make a repair...

Even more fun:

The track geometry car was just the first.  Stanley Crane began beefing up the business car fleet in earnest.  Next was a "theater car", CR9.  This time, Conrail took on the work themselves.  The Reading shops had been doing a lot of caboose work, but they had experience with passenger equipment from the pre-Conrail days when they maintained trains for SEPTA.  It turns out, they could do first-rate work.  Each car they transformed came out beautifully.

This time, designing the springs was no problem.  The trucks had been modified by a rather brilliant mechanical engineer in our office to include some viscous vertical damping over the secondary springs since the original friction system had to be abandoned when rebuilding the trucks.  

The car was nearly complete when we took it on a shake-down trip.  I borrowed the accelerometer package from Amtrak - a Metroliner round trip to DC for me!     

The car was switched out of the shop at Reading and weighed.  Very close to estimates.  The trip included the dining car staff.  They wanted to try out the kitchen, particularly the open grill that was installed.  I set up the accelerometer as close to the bolster center of the theater end as possible - which meant I had to hold down a theater seat for the whole trip!  Everyone piled on and off we went to Philadelphia, 30th Street Station.  

Backing out of 30th Street Staion

Theater seating with Amtrak's accelerometer on the floor
 On the return trip, the chef starting cooking steak and eggs.  He had enough to feed everyone and the staff was happy to serve everyone in the dining area of the car with full linen tablecloths and everything!  This was really shaping up to be one tough day of work!


Smoke.   Coming from the kitchen.  Smelled like steak!  Yum.  Too much smoke.  Getting thicker.  The grill worked fine, but the ventilation fan was too small.  Train stops in West Falls.  Everyone off!  

Now, what.  We take some time and inspect the trucks.  Everything is working perfectly.  They get the car cleared of smoke and we pile back on.  Looks like no steak and eggs for us, though.  But, no!  The chef pan fries the steaks and we get fed a wonderful meal!  Back to Reading.  Everyone piles off and I head home.  
Lunch!  Dining car crew seated at end of table.
Passing a freight on the way back to Reading
The suspension was a bit bouncy so they tweaked the damping a bit (bigger shocks), and CR9 was good to go.  It remains in service in CSX's business car fleet to this day.

Conrail went on to amass a fairly large stable of business cars.  Except for CR8 (http://blerfblog.blogspot.com/2014/08/war-stories-episode-22-lil-abners-got.html), nearly all were rebuilt in-kind, so didn't require any particular spring work or ride tests.

Rats.  But it was fun while it lasted!

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